The terminal portion of the alimentary canal extending from the rectum to its distal opening, the anus.
A passage leading form the rectum to the anus.
The terminal portion of the large intestine, its external aperture being the anus. This includes the internal and external sphincter muscles of the anus. The canal remains closed except during defecation and passage of flatus. It is about 1½ in. (3.8 cm) long.